This invention relates generally to thread cutting on lathes and more particularly relates to adapters for adjusting the lathe for extra non-standard thread cutting.
In many of the lathes now used throughout industry and science, a standard setting is provided for threads from approximately four threads per inch up to 224 threads per inch, or in the case of metric lathes, from 0.075 to 5mm (millimeter) pitch. Thread settings are selected by adjusting a gear box or with change gears. When odd-size threads in between these settings are needed, there is no way known by which they can be readily machined without adding gears for each circumstance. Various devices have been invented for attachment to lathes for making a variety of machine cuts, but there are no known devices available which can be used to set the lathe for cutting non-standard threads automatically.